The field of the present invention is starters for automotive engines. More particularly, the present invention relates to an engine starter of the type wherein a driven gear operated at a reduced speed by the rotor of a starting motor and an output shaft operably connected to said driven gear for driving a pinion gear that meshes with a ring gear of an engine are connected to each other through a unidirectional clutch that transmits the driving force only unidirectionally from the driven gear to the output shaft. Engine starters of this type are described, for example, in U.S. Pat. No. 4,440,033.
In such apparatus there generally occurs a positive load state in which the pinion gear mounted on the operating shaft drives the ring gear. Due primarily to the compression and expansion strokes of the engine at the time of cranking the engine by the engine starter, however, there may also occur a reverse load state in which the pinion is driven by the ring gear alternating in oscillating manner with the positive load state. This results in back lash noise generated by the meshed teeth of the pinion gear and the ring gear.
It is to the amelioration of this problem that the present invention is directed.